Process of manufacturing artificial paving-stones.



IWILHELM SCHUMAOHER, F oBERnoLLExnoRF, GERMANY.

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1'0 all whom it may concern:

Be it known that I, WILHELM SCHUMACH an, a citizen of the Empire of Germany, residing at Oberdollendorf, in the Empire of Germany,

5 have invented a new and useful Process of' ManufactuninggArtificial Paving-Stones, of which the following is a specification.

The artificial paving-stones used up to now have on account of ditfercnt defects not found any general use. Mostof these products-such as cla stones, clinker-s, or the likedo not possess the required hardness and are therefore worn out too soon. Paving-stones made of other materials, such as the slag of copper- 5 works, are sufliciently hard; but they become Hi6 smooth and slippery after being in use for a time. Other paving-stones, such as felds ar sto s are, though very hard, yet too irialile.

ffii t h ese artificial paving-stones have there- 26 fore been found to be inferior to natural paring-stones.

My invention relates to a process of man ufacturing artificial paving-stones from sin- Ered bauxite-that is, material which is very :5 ar an p sesses at the same time a great toughness and resisting force against shocks and blows and does, moreover, on account; of its porous structure, not become smooth.

. Asis well known, bauxite is a hydrate of 30 aluminium of the formula Al20s+2H2O with a great amount of impurities, especially admixtures of ferfg oxid, uartz, titan, and

v nadium.

. My process is as follows: Bauxitc, especlally that containing the ferric oxid to a considerable extent, is heated at a high temper-w ture, if necessary, wit 1 t \e addition of fluxes\ 40 until it is Jerfectlv sintcred. It is Hm; ducel tgs x all neggsgt a suitable fineness and mixed with a hinding material, such as clav cement as )halt. or the like. -The binding maria mus )e of course 'in a powdered state, as usual in similar processes. The mixture is moistened with water as usual, and molded to the desired form an linally burn he so-obtained paving-stones are ready for use. It is easy to ascertain by trials the correct proportion between the sinteredbauxite and the binder (averaging from fifteen to thirty per eent.)in order to obtain paving-stones Specification of Letters Patent,

Application filed December 11. 1903- Serial No. 184.842-

- PROCESS OF MANUFACTURING ARTIFICIAL PAVINtEi-STONES.

Patented Jan. 2, 1906.

described as made of sand and clay in equal proportions, or of either of them, and broken stone or earth of any kind for producing a bond, which is then ground. Two parts of this bond'are next mixed with one part of sand and one part of clay, earth, or stone, all in a powdered condition and called the filler. The mixture is afterward moistened with water and molded to the desired shape, dried, and burned. No bauxite is at all named, while in my method 1 use bauxite alone or in combination with. a flux in place of the bond. Brice uses a cupola or'blast-furnace for producing his bond, while] employ a rotary kiln of any Imovin construction for heating and sintering the bauxite. Therefore both the composition and the process used by me widely differ from those described in Brices patent. I am further aware of the U nited States Patent No. 578,351, granted March 9, 1897, to Me- Connell for chrome brick, in which the method described consists in grinding chrome ore, adding, say, twenty-five per cent. of refractory clay, such as bauxite, and, say, two per cent. of milk oflime, grinding up the mixture in a wet condition, molding it to forms, and burning the latter. No bond is formed. The bauxite forms but asmall portion, while chrome ore is the principal portion of the mixture. In my method I do not use any chrome ore at all, but exclusively sinterd bauxite. Therefore my process is quite different from McConnells process.

What 1 claim as my invention, and desire to ecure by Letters Patent, is-

1. The herein-described method of producing artificial paving-stones, which consists in first heating bauxite at a high temperature until it is perfectly sintered, then reducing it to small pieces of-a suitable fineness, nextmixing it with a ground binding material, (clay, cement, asphalt and the like), afterward moistening the mixture with water and mold- 100 ing. it to stones and Iinallyburning the stones.

2. The herein-described method of produc-' ing artificial paving-stones, which consists in first heating bauxite with the addition of a flux at a high temperature until it is perfectly sintcred, then reducing it to small pieces of a suitable fineness, next mixing it with a ground binding material (clay, cement, asphalt and 5 the like), afterward moistening the mixture with water and molding it to stones and finally burning the stones.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILHELM SCH UMACH ER.

Witnesses:

GUSTAV Enson, WILHELM KUPPER. 

